RESEARCHERS DRILL
SOUTH POLE SNOWPACK
TO DETERMINE CENTURY'S AIR QUALITY

A team of university and NOAA
scientists will search the snowpack for 100 year- old air samples
at the South Pole this January, to investigate what the air quality
was like during the last century.

The pockets of air trapped in the snowpack
will provide scientists with a historical record of gases that
were present in the atmosphere during this period. Researchers
will then be able to analyze this record for clues to how human
activity has influenced atmospheric processes.

"It is important that we get these
air samples now,"said Jim Butler of NOAA. "Each year
we delay, we lose a year of history, as the snow turns to ice
at the bottom of the hole. Just a few years from now, we will
not be able to obtain air samples that span the entire 20th century,
a time of rapid population, agricultural, and industrial growth."

Recent studies by the same research team
published in the journal Nature
in1996 and in 1999, indicated that the composition of the atmosphere
has changed dramatically over the past 100 years, presumably
because of human activities.

These previous studies demonstrated the
feasibility of obtaining representative atmospheric histories
from air trapped in the snowpack that sits atop the polar ice
sheets.

Although longer histories of some gases
can be obtained from ice cores, the gas samples are tiny. Current
analytical techniques do not allow for accurate measurement of
trace gases in these minute amounts. In the snowpack, however,
the amount of air is essentially unlimited. This allows for high-precision
measurement of gases that occur in very low concentrations in
the atmosphere.

According to Mark Battle of Bowdoin College
and leader of the expedition, "One of the things we learned
from our previous work was just how good these samples can be.
Now we're in a position to reconstruct the histories of some
gases with a precision we never imagined six years ago."

Large amounts of the old air will be stored
at the NOAA facility in Boulder, Colo., in what's known as an
air archive. This archive will be available for future analyses,
to answer questions that haven't even been thought of yet, and
with techniques yet to be developed.

Due to the scientific requirements of the
project, the field team will be camping near the South Pole while
they drill, instead of residing inside the permanent facility
at the South Pole.

"We'll be extracting air from undisturbed
snowpack, so we need to be located far from other activities
going on at the South Pole," Butler said. Temperatures at
the South Pole in January range from -11 to -40 degrees Fahrenheit
and windspeeds average about 11 miles per hour.